Currently available epoxy and vinyl ester resins with good chemical resistance are brittle. FRP pipe lined with these resins often fail at impact generated cracks. Previous attempts to flexibilize epoxy and vinyl ester resins resulted in drastic loss of chemical resistance properties. See, for example, U.S. Pat. Nos. 3,928,491 and 4,018,250; also sales literature distributed by the B. F. Goodrich Company on so-called CTBN and ATBN resins.
An epoxy ester resin has low chemical resistance because its ester linkages are inherently susceptible to hydrolysis.
There is a need for a flexibilized epoxy or vinyl ester resin having good chemical resistance for use with FRP pipe linings, and for coating steel tanks, piping, and concrete.